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Old 12-16-2011, 06:55 AM   #1 (permalink)
stillsearching
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Join Date: Dec 2011
Location: Minnesota
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DIY CNG refueling?

I would swear I already posted a CNG related thread on ecomodder but searching for it I cannot find it. :-/ If you saw my other post please link me to it and tell me what i'm doing wrong as far as posting or searching. I tried searching for my own name unless my post got deleted for being in the wrong place or something.


I have been investigating CNG fuel options which as far as I can tell seems to be one of The Answers for interim fuel savings... the only problem is the COST. A typical commercial setup costs $15,000-20,000 by the time you bring it all home. More if you are custom converting a car not made for it from the factory, and used CNG vehicles are hard to come by if available at all.

I live in minnesota - there is only one CNG refueling station and it's price is so high I might as well be using gasoline. (gasoline is the same price) It's not like Utah or something where it's 1/4 the cost. But i'd still like to experiment with it.

Home refueling is the ONLY way to make it work, but although there seems to be homebrew ways to do CNG conversions of a vehicle or engine a big problem seems to be the home CNG refueling itself... the only one I know of is just called Fuelmaker Phill and costs like $6000 with a waiting time of months (and wasn't even available for a period of a year and a half during some problem I didn't understand, plus others have said it was unreliable, and an unreliable setup with a company that may or may not even be in business in a few years seems iffy), plus another $1000-1500 at least to install it at your home. This is before you even have a CNG vehicle.

When you are already planning on driving something efficient and small, the savings per mile is less, so it takes longer for CNG to pay for itself. It makes more sense on taxis and fleet vehicles, but if refueling could be done cheap enough at home it becomes an option. Also the rate of Fuelmaker Phill may not be enough for some of us with more extensive commuting and after work needs (just under 1/2 gallon gas equivalent per hour, 16hrs to fill a typical honda GX tank from empty, from my calculations I could do my planned college commuting but NOT do my normal work rounds after school and still get back home with either enough time to fuel up completely or possibly even enough fuel to complete them) Therefore the need for a slightly larger (or even smaller, for experimenters wanting to do motorcycles and such) compressor may be relevant. Also a faster rate could take advantage of off peak power rates at night in some areas perhaps paying for itself by that alone. (the Phill uses 800 watts)

There may be legal issues preventing it, but I cant see why compressing natural gas at home should be such an impossibly expensive or dangerous job. I mean we buy propane tanks and hook them up ourself to our grills, right? Besides which i'd just like to experiment with the fuel, maybe on a motorcycle or ATV first before committing to it on a car. If prices go for the sky in a year like I expect i'll then have more experience under my belt before stepping up the need for immediate conversion.

Can anyone recommend some other resources or places that at home fueling (NOT with Fuelmaker Phill but either competitors or homebrew applications) has been discussed or explored? Even with tiny tanks and low pressures a CNG runabout with a short range could have alot of utility, just like electric cars with a range of only 20-50 miles are considered still useful because the cheapness of the energy makes it worthwhile.

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